Rebuilt entire level's Terrain - Where is the file!?

I have levels/KrallThree

Yet in my /levels I have all SORTS of .ter files. Which ones are ACTUALLY needed? If I click "save as" and save as "thisIsATest" does it make a "thisIsATest.ter" and all other files?

Basically I'm trying to figure out how to do backups because of just losing a huge amount of work and time due to the editor crashing when saving and never opening the map again.

I'd like to know how to simply make backups, so that if it crashes when saving again, I don' thave to rebuild 16 square kilometers of map!! I swear guiness should have been here to witness how fast I just rebuilt the entire terrain - still not textured, and still need to smooth roads and ramps of course.

*massive sigh*
--- Post updated ---
Great, so I picked the wrong one, and now it loaded with no terrain again.

So I selected the terrain I thought it should be - as per the entire folder backup - and it imported the correct one. In the wrong place. So now nothing lines up!! OH............ MY.................... golly gosh. SUCH a learning curve with this editor :'(
--- Post updated ---
FFS.

Lined it up, then the grass went nuts and now it's 3 feet above the surface, and there's no collision on the damn terrain.

WHY THE HELL IS THIS HAPPENING :'( I've been literally busting my butt with this level and now it's all come down to stupid glitchy crap like this ruining it!?>!?
--- Post updated ---
Well I imported every .ter I had until one worked with collision. Then it happened to reset the grass issue. I've just imported the correct .ter and it worked. I'm about to hit save, and then reopen it - wish me LUCK!

YEEEESSS, I just hit F11 to test it, and the car BOUNCED OFF OF THE GROUND!!!!!!!!! How lovely the small things in life are. Now to actually close the game and reopen it.

Annnd that's a success.

WELL what have we learned:

When editing a map as large and as detailed as this (I've made every possible detail just EXACT) be sure to know proper backup methods before you get carried away and lose it all to a random crash during SAVE. After that happened, I had to rebuild the entire terrain. THEN suddenly, the grass messed up annnnnd there was no collision. Then nothing would import correctly. What I DID DO was delete create a BLANK terrain, then point that to the .ter file, and presto it worked. <--- SOLUTION

 

Each .ter file correspond to every terrain/heightmap you created/imported. The game does not remove older ones, in case you need them.
Which one you need? The most recent one supposedly (or the one that appears to be used in your level's .json files)

If you have notepad, I'd search all .json files for .ter, to quickly see which one the game is using.

 

Thanks for that, so the issue is the game says I'm using xxxx.ter but every time I save, it saves a different .ter in the /levels directory - which one should I backup? Or is the .ter in the /levels the backup? Haha sorry I'm clearly missing something here and I feel like an idiot! BTW your avatar is mesmerizing =D
--- Post updated ---
Also if you can help identify what causes the terrain to go collisionless and make the grass appear disconnected? Just to avoid this in the future, I'm so scared to work on the level again